Relay adhesion detection circuit and detection system

Abstract

The relay adhesion detection circuit comprises a first power supply, a main positive relay connected with the positive electrode of the first power supply, a load, a shunt connected with the negative electrode of the first power supply, and a high-voltage main loop formed by a main negative relay, two ends of the main positive relay are connected in parallel with a pre-charging relay and a pre-charging resistor; the detection loop is connected in parallel with the high-voltage main loop; the detection loop, the main positive relay, the main negative relay and the pre-charging relay form a first loop, a second loop and a third loop respectively; wherein the first loop, the second loop and the third loop are respectively used for detecting whether the main positive relay, the main negative relay and the pre-charging relay are adhered or not. According to the scheme, through the first loop, the second loop and the third loop, whether one of the main positive relay, the main negative relay and the pre-charging relay is adhered or not can be detected, and meanwhile, whether the main positive relay, the main negative relay and the pre-charging relay are adhered or not can be detected.

Description

Technical Field

[0001] This application relates to the field of electronic detection technology, and particularly to a relay adhesion detection circuit and a detection system. Background Art

[0002] Electric vehicles are a new energy industry strongly advocated by the country. As vehicles powered by electricity, the battery system (referring to the power source of electric vehicles) is the core component of electric vehicles. The high-voltage main circuit relay of an electric vehicle controls the discharge of the battery system, and the reliable operation of this relay is directly related to the safety of electric vehicles. An electric vehicle operating in a state where the relay is adhered may cause a safety accident. If a false alarm occurs in the adhesion detection of the relay, the electric vehicle will not be able to start. Therefore, the battery management system (BMS) needs to reliably detect the adhesion state of the relay.

[0003] At present, although some relay adhesion detection schemes based on voltage detection or current detection have been proposed, most of the existing schemes can only detect whether a certain relay is adhered, and cannot detect the situation where multiple relays are adhered simultaneously. Utility Model Content

[0004] This application aims to at least solve one of the technical problems existing in the prior art. For this reason, this application proposes a relay adhesion detection circuit and a detection system to solve one or more problems existing in the prior art detection methods.

[0005] In a first aspect, this application provides a relay adhesion detection circuit, including a high-voltage main circuit formed by a first power supply B1, a main positive relay K1 connected to the positive pole of the first power supply B1, a load 100, a shunt FL, and a main negative relay K2 connected in series in sequence, with a pre-charge relay K3 and a pre-charge resistor R1 connected in parallel across the main positive relay K1, and further including a detection circuit connected in parallel with the high-voltage main circuit;

[0006] The detection circuit forms a first circuit 310, a second circuit 320, and a third circuit 330 with the main positive relay K1, the main negative relay K2, and the pre-charge relay K3 respectively;

[0007] Among them, the first circuit 310, the second circuit 320, and the third circuit 330 are respectively used to detect whether the main positive relay K1, the main negative relay K2, and the pre-charge relay K3 are adhered.

[0008] Through the embodiments of this application, it is possible to detect whether a certain one of the main positive relay, the main negative relay, and the pre-charge relay is adhered, and at the same time, it is also possible to detect whether the main positive relay, the main negative relay, and the pre-charge relay are adhered simultaneously.

[0009] In a technical solution of the above relay adhesion detection circuit, the detection loop includes a second power supply B2, a detection element 200, a first resistor R2, a first diode D1, and a second diode D2;

[0010] The second power supply B2, the first diode D1, the main positive relay K1, the first resistor R2, the second diode D2, and the detection element 200 are connected to each other to form the first loop 310.

[0011] In a technical solution of the above relay adhesion detection circuit, the second power supply B2, the first diode D1, the pre-charge resistor R1, the pre-charge relay K3, the first resistor R2, the second diode D2, and the detection element 200 are connected to each other to form the third loop 330.

[0012] In a technical solution of the above relay adhesion detection circuit, the detection loop further includes a second resistor R3, a third diode D3, and a fourth diode D4;

[0013] The second power supply B2, the third diode D3, the main negative relay K2, the second resistor R3, the fourth diode D4, and the detection element 200 are connected to each other to form the second loop 320.

[0014] In the embodiment of the present application, by judging the detection signal detected by the detection element 200, it is possible to detect whether any one of the main positive relay, the main negative relay, and the pre-charge relay is adhered, and at the same time, it is also possible to detect whether they are adhered simultaneously. Moreover, the detection loop is independently powered by the second power supply B2, which can not only improve the monitoring efficiency but also achieve uninterrupted detection.

[0015] In a technical solution of the above relay adhesion detection circuit, the resistance values of the pre-charge resistor R1, the first resistor R2, and the second resistor R3 are all not equal.

[0016] By setting the resistance values of the pre-charge resistor R1, the first resistor R2, and the second resistor R3 to be all not equal, it is possible to judge the adhesion situation of each relay by different detection signals (such as current, etc.) detected by the detection element 200.

[0017] In a technical solution of the above relay adhesion detection circuit, the anodes of the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 are connected to the positive pole of the second power supply B2.

[0018] In one technical solution of the above relay adhesion detection circuit, a first switch K4, a second switch K5, and a third switch K6 are respectively connected in series in the first loop 310, the second loop 320, and the third loop 330.

[0019] In one technical solution of the above relay adhesion detection circuit, by closing any one or more of the first switch K4, the second switch K5, and the third switch K6 and opening the remaining switches, it is detected whether the relay corresponding to the closed switch is adhered.

[0020] In one technical solution of the above relay adhesion detection circuit, the detection loop further includes a thermistor PTC connected in series with the detection element 200, and the thermistor PTC is used for overcurrent protection of the detection loop.

[0021] In a second aspect, the present application provides a detection system, including the relay adhesion detection circuit according to any one of the first aspect.

[0022] One or more of the above technical solutions of the present application at least have one or more of the following beneficial effects:

[0023] In implementing the technical solution of the present application, by providing a detection loop in parallel with the high-voltage main loop, and using the detection loop to form the first, second, and third loops with the main positive relay, the main negative relay, and the pre-charge relay respectively, through the first, second, and third loops, it is possible to detect whether any one of the main positive relay, the main negative relay, and the pre-charge relay is adhered, and at the same time, it can also detect whether they are adhered simultaneously; further, the detection loop is independently powered by a second power supply, which can not only improve the monitoring efficiency but also achieve uninterrupted detection.

[0024] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Referring to the accompanying drawings, the disclosure of the present application will become more understandable. It is easily understood by those skilled in the art that: these drawings are only for illustrative purposes and are not intended to limit the protection scope of the present application. In addition, similar numbers in the drawings are used to represent similar components, where:

[0026] Figure 1 is a schematic structural diagram of the relay adhesion detection circuit provided in Embodiment 1 of the present application;

[0027] Figure 2 is a schematic structural diagram of the high-voltage main loop provided in Embodiment 1 of the present application;

[0028] Figure 3It is a schematic structural diagram of the first loop of the relay adhesion detection circuit provided in the first embodiment of the present application-

[0029] Figure 4 It is a schematic structural diagram of the second loop of the relay adhesion detection circuit provided in the first embodiment of the present application-

[0030] Figure 5 It is a schematic structural diagram of the third loop of the relay adhesion detection circuit provided in the first embodiment of the present application;

[0031] Figure 6 It is a schematic structural diagram of the relay adhesion detection circuit provided in the second embodiment of the present application;

[0032] Figure 7 It is a schematic structural diagram of the relay adhesion detection circuit provided in the third embodiment of the present application-

[0033] Figure 8 It is a schematic structural diagram of the relay adhesion detection circuit provided in the fourth embodiment of the present application. Specific embodiments

[0034] The following describes some embodiments of the present application with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present application and are not intended to limit the protection scope of the present application.

[0035] As described in the background art, although some relay adhesion detection schemes based on voltage detection or current detection have been proposed in the prior art, most of the existing schemes can only detect whether a certain relay is adhered, and cannot detect the situation where multiple relays are adhered simultaneously.

[0036] Based on the above problems, the embodiments of the present application creatively propose a new relay adhesion detection circuit and detection system based on current detection. The relay adhesion detection circuit is provided with a detection loop in parallel with the high-voltage main loop, and the detection loop is respectively composed of the main positive relay, the main negative relay, and the precharge relay to form the first, second, and third loops. Through the first, second, and third loops, it is possible to detect whether a certain one of the main positive relay, the main negative relay, and the precharge relay is adhered, and at the same time, it can also detect whether they are adhered simultaneously; further, the detection loop is independently powered by a second power source, which can not only improve the monitoring efficiency but also achieve uninterrupted detection.

[0037] Embodiment 1

[0038] Figure 1 It is a schematic structural diagram of the relay adhesion detection circuit provided in the embodiment of the present application. Refer to Figure 1As shown, the relay adhesion detection circuit generally includes components such as a first power supply B1, a main positive relay K1, a load 100, a shunt FL, a main negative relay K2, a pre-charge relay K3, and a pre-charge resistor R1. Refer to Figure 2 As shown, the main positive relay K1, the load 100 are connected to the positive pole of the first power supply B1, and the shunt FL, the main negative relay K2 are connected to the negative pole of the first power supply B1 to form a high-voltage main circuit. The pre-charge relay K3 and the pre-charge resistor R1 are connected in parallel across the two ends of the main positive relay K1.

[0039] Further refer to Figure 2 As shown, in some specific embodiments, the load 100 may be a parallel circuit composed of a capacitor C0 and a resistor R0. It can be understood that in the high-voltage main circuit of an electric vehicle, the first power supply B1 is generally a battery pack, and the load 100 is usually a capacitive load. It can be understood that the load 100 is usually a motor in an electric vehicle, where the capacitor C0 is the capacitor of the motor frequency converter. The voltage difference across the two ends of the first power supply B1 is called the PACK voltage, and the voltage difference across the two ends of the load 100 is called the LINK voltage. The voltages at the positive and negative ends of the first power supply B1 are the PACK+ voltage and the PACK- voltage respectively, and the voltages across the two ends of the load 100 are the LINK+ and LINK- voltages respectively. Therefore, the voltages across the two ends of the main positive relay K1 are the PACK+ voltage and the LINK+ voltage respectively, and the voltages across the two ends of the main negative relay K2 are the PACK- voltage and the LINK- voltage respectively.

[0040] It can be understood that the traditional relay adhesion detection method based on voltage detection usually judges whether the main positive relay or the main negative relay is adhered by detecting the voltages across the two ends of the main positive relay and the main negative relay respectively. This method usually requires a very strong discharge circuit, which is prone to arcing. This is because the capacitor C0 of the motor frequency converter is very large. If there is no very strong discharge circuit, the voltage drop will be very slow, and the permanent magnet synchronous motor used in electric vehicles has the ability of energy feedback, resulting in the LINK voltage and the pack voltage being close, which is prone to false detection. Since the discharge circuit will be damaged during use and the discharge circuit will generate heat, it is best not to set up a discharge circuit considering that the capacitor will not be touched. However, without a discharge circuit, due to the existence of the capacitor C0 of the motor controller and the motor power generation effect under different road conditions, factors such as continuous power on and off, natural discharge without a discharge resistor, and motor feedback, when the LINK voltage at the capacitive load end of the relay is close to the PACK voltage, the voltage detection method will think that the relay is adhered, but in fact the relay is not adhered, resulting in detection errors. At the same time, without a discharge circuit, due to the very slow voltage drop, the detection time will be too long. A too long detection time means untimely detection, which will pose a great safety hazard to electric vehicles.

[0041] Based on this, the relay adhesion detection circuit provided by the embodiments of the present application further includes a detection circuit connected in parallel with the high-voltage main circuit. In order to be able to detect whether any one of the main positive relay K1, the main negative relay K2, and the pre-charge relay K3 is adhered, and at the same time be able to detect whether the main positive relay K1, the main negative relay K2, and the pre-charge relay K3 are adhered simultaneously, the detection circuit provided by the embodiments of the present application respectively forms a first loop 310, a second loop 320, and a third loop 330 with the main positive relay K1, the main negative relay K2, and the pre-charge relay K3. Among them, the first loop 310 is used to detect whether the main positive relay K1 is adhered, the second loop 320 is used to detect whether the main negative relay K2 is adhered, and the third loop 330 is used to detect whether the pre-charge relay K3 is adhered.

[0042] Further referring to Figure 1 and Figures 3 to 5 As shown, in some specific embodiments, the detection circuit includes a second power supply B2, a detection element 200, a first resistor R2, a second resistor R3, a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. Among them, the second power supply B2, the first diode D1, the main positive relay K1, the first resistor R2, the second diode D2, and the detection element 200 are sequentially connected to form the first loop 310; the second power supply B2, the third diode D3, the main negative relay K2, the second resistor R3, the fourth diode D4, and the detection element 200 are sequentially connected to form the second loop 320; the second power supply B2, the first diode D1, the pre-charge resistor R1, the pre-charge relay K3, the first resistor R2, the second diode D2, and the detection element 200 are sequentially connected to form the third loop 330.

[0043] It can be understood that using an independent second power supply B2 to provide a detection current for the detection circuit can improve the detection efficiency and can achieve uninterrupted detection. It should be noted that in the embodiments of the present application, the specific implementation of the second power supply B2 is not limited. Without departing from the inventive concept of the present application, the user can select according to actual needs. For example, the second power supply B2 can be a current source.

[0044] It can be understood that in the embodiments of the present application, the detection element 200 can be communicatively connected to a battery management system (BMS) or the like, so that the battery management system (BMS) can determine the adhesion condition of each relay according to different detection signals (such as current) detected by the detection element 200. It should be noted that in the embodiments of the present application, the specific implementation of the detection element 200 is not limited, and the user can select according to actual needs without departing from the inventive concept of the present application. For example, the detection element 200 can be any one of a shunt, a light-emitting element, or a sound-emitting element. It can be understood that when the detection element 200 is a shunt, the adhesion of a certain relay or certain relays can be determined by the current signal detected by the shunt. When the detection element 200 is a light-emitting element or a sound-emitting element, a light-emitting element or a sound-emitting element can be adaptively connected in series in each loop respectively. If the light-emitting element in a loop emits light or the sound-emitting element makes a sound, it is determined that the relay corresponding to this loop is adhered. The following will illustrate the solution of the present application by taking the detection element 200 as a shunt as an example.

[0045] As a preferred embodiment, in the embodiments of the present application, the resistance values of the pre-charge resistor R1, the first resistor R2, and the second resistor R3 are set to be unequal to limit the magnitude of the current in each loop, so as to realize the determination of the adhesion condition of each relay by different detection signals (such as current) detected by the detection element 200.

[0046] In some specific embodiments, the difference between the resistance values of the pre-charge resistor R1, the first resistor R2, and the second resistor R3 is greater than a preset threshold value. The specific value of the preset threshold is not limited. Exemplarily, the preset threshold can be 10Ω or 20Ω.

[0047] In some other specific embodiments, the resistance value of the first resistor R2 is greater than the resistance value of the second resistor R3 and less than the resistance value of the pre-charge resistor R1.

[0048] It should be noted that in the embodiments of the present application, the resistance values of the pre-charge resistor R1, the first resistor R2, and the second resistor R3 are not specifically limited. Without departing from the inventive concept of the present application, they can be set according to actual detection needs. As an illustrative rather than restrictive example, the resistance value of the pre-charge resistor R1 is 50Ω - 100Ω, R2 = 30Ω, R3 = 10Ω, and the resistance of the relay is in the milliohm level, which can be not considered compared with the pre-charge resistor R1, the first resistor R2, and the second resistor R3 and has little influence, and is defaulted to a wire.

[0049] It can be understood that in the embodiments of the present application, the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 have the same specifications and have unidirectional conductivity. The anodes of the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 are connected to the positive pole of the second power supply B2, so as to play a role in restricting the direction of the detection current in each loop.

[0050] Further referring to Figure 1 and Figures 3 to 5 as shown, taking the detection element 200 as a shunt and the voltage of the second power supply B2 as V as an example, the detection principle of the relay adhesion detection circuit provided by the solution of the present application is described as follows:

[0051] 1. When the main positive relay K1 is stuck, the current loop should be: the second power supply B2 → D1 → K1 → R2 → D2 → shunt 200. Therefore, when the current value detected by the shunt 200 is , it can be determined that the main positive relay K1 is stuck.

[0052] 2. When the main negative relay K2 is stuck, the current loop should be: the second power supply B2 → D3 → K2 → R3 → D4 → shunt 200. Therefore, when the current value detected by the shunt 200 is , it can be determined that the main negative relay K2 is stuck.

[0053] 3. When the precharge relay K3 is stuck, the current loop should be: the second power supply B2 → D1 → R1 → K3 → R2 → D2 → shunt 200. Therefore, when the current value detected by the shunt 200 is , it can be determined that the precharge relay K3 is stuck;

[0054] 4. When the main positive relay K1 and the main negative relay K2 are stuck at the same time, the two current loops should be: the second power supply B2 → D1 → K1 → R2 → D2 → shunt 200 - the second power supply B2 → D3 → K2 → R3 → D4 → shunt 200. Therefore, when the current value detected by the shunt 200 is I4 = I1 + I2, it can be determined that the main positive relay K1 and the main negative relay K2 are stuck at the same time;

[0055] 5. When the main positive relay K1 and the precharge relay K3 are stuck at the same time, the two current loops should be: the second power supply B2 → D1 → K1 → R2 → D2 → shunt 200; the second power supply B2 → D1 → R1 → K3 → R2 → D2 → shunt 200. Therefore, when the current value detected by the shunt 200 is I5 = I1 + I3, it can be determined that the main positive relay K1 and the precharge relay K3 are stuck at the same time.

[0056] 6. When the main negative relay K2 and the pre-charge relay K3 are simultaneously stuck, the two current loops should be: the second power supply B2 → D3 → K2 → R3 → D4 → shunt 200; the second power supply B2 → D1 → R1 → K3 → R2 → D2 → shunt 200. Therefore, when the current value detected by the shunt 200 is I6 = I2 + I3, it can be determined that the main negative relay K2 and the pre-charge relay K3 are simultaneously stuck;

[0057] 7. When the main positive relay K1, the main negative relay K2, and the pre-charge relay K3 are simultaneously stuck, the three current loops should be: the second power supply B2 → D1 → K1 → R2 → D2 → shunt 200; the second power supply B2 → D3 → K2 → R3 → D4 → shunt 200; the second power supply B2 → D1 → R1 → K3 → R2 → D2 → shunt 200. Therefore, when the current value detected by the shunt 200 is I7 = I1 + I2 + I3, it can be determined that the main positive relay K1, the main negative relay K2, and the pre-charge relay K3 are simultaneously stuck.

[0058] It can be understood that the resistance values of the pre-charge resistor R1, the first resistor R2, and the second resistor R3 are set to be different. Since the difference between the detected currents is a bit larger, the detection can be made more accurate. Therefore, it can be set that R1 ≠ R2 ≠ R3, R1 ≠ R2 + R3, R3 ≠ R1 + R2, and R2 ≠ R1 + R3.

[0059] Embodiment 2

[0060] The difference from Embodiment 1 is that in this embodiment of the present application, switches are added to the circuits for detecting the sticking of each relay. Refer to Figure 6 As shown, a first switch K4 is connected in series in the first loop 310, a second switch K5 is connected in series in the second loop 320, and a third switch K6 is connected in series in the third loop 330. As an illustrative but not restrictive example, the on / off of the first switch K4, the second switch K5, and the third switch K6 can be controlled by the battery management system. By closing any one or more of the first switch K4, the second switch K5, and the third switch K6 and opening the remaining switches, it is possible to detect whether the relay corresponding to the closed switch is stuck. It can be understood that when detecting the sticking of a single relay, by closing the corresponding switch to turn off other detection circuits, not only can the power energy be saved (the resistor will consume energy), but also the sticking detection of a single relay can be more accurately achieved because at this time the influence of the sticking of other relays can be excluded, and even if other relays are stuck, it will not affect the detection accuracy. Of course, it is also possible to close multiple switches to simultaneously detect whether multiple relays are stuck. The specific detection principle is as follows:

[0061] 1. Close the first switch K4 and open the second switch K5 and the third switch K6. At this time, the current loop is: the second power supply B2 → R2 → D1 → K1 → K4 → D2 → shunt 200. If the shunt 200 detects a current signal, it can be determined that the main positive relay K1 is stuck.

[0062] 2. Close the second switch K5 and open the first switch K4 and the third switch K6. At this time, the current loop is: the second power supply B2 → R3 → D3 → K2 → K5 → D4 → shunt 200. If the shunt 200 detects a current signal, it can be determined that the main negative relay K2 is stuck.

[0063] 3. Close the first switch K4 and the third switch K6 and open the second switch K5. At this time, the current loop is: the second power supply B2 → R2 → D1 → R1 → K3 → K6 → K4 → D2 → shunt 200. If the shunt 200 detects any current signal, it can be determined that the pre-charge relay K3 is stuck.

[0064] 4. Open the third switch K6, first close the first switch K4, and then close the second switch K5 after a delay. There are two current loops: the second power supply B2 → R2 → D1 → K1 → K4 → D2 → shunt 200; the second power supply B2 → R3 → D3 → K2 → K5 → D4 → shunt 200. If the shunt detects current values during both switch closures, it can be determined that the main positive relay K1 and the main negative relay K2 are stuck simultaneously.

[0065] 5. Open the second switch K5, first close the first switch K4, and then close the third switch K6 after a delay. If the shunt detects current values during both switch closures in the loop, it can be determined that the main positive relay K1 and the pre-charge relay K3 are stuck simultaneously.

[0066] 6. First close the second switch K5, and then close the third switch K6 and the first switch K4 after a delay. If the shunt 200 detects current values during both switch closures in the loop, it can be determined that the main negative relay K2 and the pre-charge relay K3 are stuck simultaneously.

[0067] 7. Close the second switch K5, the first switch K4, and the third switch K6 in sequence. If the shunt 200 detects current values during all three switch closures in the loop, it can be determined that the main positive relay K1, the main negative relay K2, and the pre-charge relay K3 are stuck simultaneously.

[0068] In summary, keep other switches open, close any switch in a detection loop. If a current signal is detected, it can be determined that the relay in that loop is stuck. Close other switches in sequence, and each time a switch is closed, it can be detected whether the relay in that loop is stuck. During subsequent detection, the previously closed switch can be opened to save energy, or it can be kept closed without affecting the detection result.

[0069] Embodiment III

[0070] The difference from Embodiment I is that in the embodiment of the present application, a thermistor PTC is added to the detection circuit. Refer to Figure 7 As shown, the thermistor PTC is connected in series with the detection element 200. In case of an abnormality, the main positive relay K1 is disconnected and the main negative relay K2 is closed. At this time, the large voltage of LINK+ will be directly connected to the adhesion detection circuit. The thermistor PTC can effectively prevent the current in the circuit from being too large and damaging the circuit, that is, the thermistor PTC can be used for overcurrent protection of the detection circuit.

[0071] Embodiment IV

[0072] The difference from Embodiment I is that in the embodiment of the present application, the second power supply B2 uses a power converter. Refer to Figure 8 As shown, as a preferred embodiment, the second power supply B2 is a DC-DC converter, which converts the voltage of the first power supply B1 into the voltage required by the adhesion detection circuit through a DC / DC converter. The shunt uploads the current value of the detection circuit to the BMS system for analysis and judgment. This solution does not require an external power supply to be reconnected, greatly realizing the operability of this circuit.

[0073] Embodiment V

[0074] Corresponding to the above Embodiments I to IV, the present application also provides a detection system, which includes the relay adhesion detection circuit described in any one of Embodiments I to IV. In this embodiment, the content that is the same as or similar to the above Embodiments I to IV can be referred to the above introduction and will not be repeated hereinafter.

[0075] Each embodiment in this specification is described in a progressive manner. The same or similar parts between each embodiment can be referred to each other, and the key points of each embodiment are the differences from other embodiments.

[0076] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0077] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0078] In the present application, unless otherwise clearly stipulated and defined, terms such as "installed", "connected", "joined", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0079] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A relay adhesion detection circuit, comprising a high-voltage main circuit formed by sequentially connecting in series a first power supply (B1), a main positive relay (K1) connected to the positive pole of the first power supply (B1), a load (100), a shunt (FL) connected to the negative pole of the first power supply (B1), and a main negative relay (K2). A precharge relay (K3) and a precharge resistor (R1) are connected in parallel across the two ends of the main positive relay (K1), and is characterized in that, It also includes a detection circuit connected in parallel with the high-voltage main circuit; The detection circuit respectively forms a first circuit (310), a second circuit (320), and a third circuit (330) with the main positive relay (K1), the main negative relay (K2), and the pre-charge relay (K3). Among them, the first circuit (310), the second circuit (320), and the third circuit (330) are respectively used to detect whether the main positive relay (K1), the main negative relay (K2), and the pre-charge relay (K3) are stuck.

2. The relay adhesion detection circuit according to claim 1, characterized in that, The detection circuit includes a second power supply (B2), a detection element (200), a first resistor (R2), a first diode (D1), and a second diode (D2); The second power supply (B2), the first diode (D1), the main positive relay (K1), the first resistor (R2), the second diode (D2), and the detection element (200) are connected to each other to form the first circuit (310).

3. The relay adhesion detection circuit according to claim 2, wherein The second power supply (B2), the first diode (D1), the pre-charge resistor (R1), the pre-charge relay (K3), the first resistor (R2), the second diode (D2), and the detection element (200) are connected to each other to form the third circuit (330).

4. The relay adhesion detection circuit according to claim 3, wherein, The detection circuit further includes a second resistor (R3), a third diode (D3), and a fourth diode (D4); The second power supply (B2), the third diode (D3), the main negative relay (K2), the second resistor (R3), the fourth diode (D4), and the detection element (200) are connected to each other to form the second circuit (320).

5. The relay adhesion detection circuit according to claim 4, wherein The resistance values of the pre-charge resistor (R1), the first resistor (R2), and the second resistor (R3) are not equal.

6. The relay adhesion detection circuit according to claim 4, wherein, The anodes of the first diode (D1), the second diode (D2), the third diode (D3), and the fourth diode (D4) are connected to the positive pole of the second power supply (B2).

7. The relay adhesion detection circuit according to claim 4, characterized in that, A first switch (K4), a second switch (K5), and a third switch (K6) are respectively connected in series in the first circuit (310), the second circuit (320), and the third circuit (330).

8. The relay adhesion detection circuit according to claim 7, wherein, By closing any one or more of the first switch (K4), the second switch (K5), and the third switch (K6) and opening the remaining switches, it is detected whether the relay corresponding to the closed switch is stuck.

9. The relay adhesion detection circuit according to claim 4, wherein The detection circuit further includes a thermistor (PTC) connected in series with the detection element (200), and the thermistor (PTC) is used for over-current protection of the detection circuit.

10. A detection system, characterized in that: It includes the relay stuck detection circuit according to any one of 1-9 above.

Images